


Best Birthday Ever

by TheCaptinofSirius



Series: SenGen week 2020 [7]
Category: Dr. STONE (Anime), Dr. STONE (Manga)
Genre: Alternate Universe - Modern Setting, Family Fluff, M/M, Soulmate-Identifying Marks
Language: English
Status: Completed
Published: 2021-01-04
Updated: 2021-01-04
Packaged: 2021-03-10 20:53:39
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,076
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28413447
Author URL: https://archiveofourown.org/users/TheCaptinofSirius/pseuds/TheCaptinofSirius
Summary: Senku's day just keeps getting better and better, but he just can't put his finger on why. When he returns home that night to a surprise party, he realizes it's his birthday.
Relationships: Asagiri Gen/Ishigami Senkuu
Series: SenGen week 2020 [7]
Series URL: https://archiveofourown.org/series/2080911
Comments: 1
Kudos: 53





	Best Birthday Ever

**Author's Note:**

> SenGen Week 2020 - Day 7  
> Prompt - senku's birthday!/ ~~free choice~~
> 
> I really wanted to do a soulmate AU for SenGen week, but I wasn't able to fit it in my plans. Enjoy the slightest bit of it in this cuddly family fic!
> 
> Disclaimer: I have no idea if Senku was actually born in 2004. It's just my rough estimate off of the timeline I put together from the manga.

Senku was beyond satisfied as he left the lab that night. He managed to not only complete his latest project, but make a decent amount of headway on the next.

He climbed in to his car, grinning when his favorite song came on the radio. Honestly the entire day had been surreal. Gen had woken him up with a fantastic blow job. His three kids were on their best behavior this morning, and even volunteered to do the dishes.

Chrome had bought him breakfast, and Taiju took him out to his favorite place for lunch.

So when he came home and found the lights off, he was more than a little confused.

“Surprise!” The room called as he turned on the light. His eyes widened as he noticed all of his friends and family in one room. He grinned as he caught sigh of the large “Happy birthday Senku” banner behind them.

“It’s my birthday?” He asked as his children ran over and hugged him. Gen sent a smug grin to Chrome, holding out his hand.

“Pay up. Told you I could do it.” He said. Chrome groaned, passing him a wad of cash.

“Really? You pranked me on my birthday?” He asked, even as he kept the smile on his face. Gen closed his fingers over the money before approaching his husband, kissing him in greeting before handing him the money.

“And I got you $100. You’re welcome, and happy birthday my dear.” He said before kissing him again. Senku chuckled, winding his arms around his waist as he kissed him back.

“Best soulmate ever.” He murmured against his lips. Gen smiled, reaching up to press against the rocket on Senku's shoulder. A matching one sat on Gen's shoulder.

“Alright, break it up. There are kids here.” Kohaku scowled.

“The cake will be ready in about 20 minutes, Senku.” Yuzuriha spoke up.

“And dinner is done!” Taiju called out from the kitchen. Shaking his head, Senku pulled back from his husband. As he went to join his family, he thought about how lucky he was.

He and Gen had met in the first lab Senku officially worked in. Gen was working in the same building at one of the psychology labs, and they became fast friends when they managed to put some know-it-all macho jerk in his place.

  
Two weeks later and they were dating. The topic of soulmates came out during lunch, and as Gen was describing his, Senku had laughed.

_“I never thought it was possible for me to have a soulmate. Byakuya and Taiju used to say that the rocket was a sign of my love for space.”_ He had explained as he opened up the top of his shirt to show off the rocket on his shoulder. Gen had beamed, eagerly pulling down the collar of his shirt to reveal a matching one.

“Daddy, how old are you now?” Senku's only daughter's question pulled him out of his musing. He sat down next to Tsukasa, nodding at his friend before pulling Rika in to his arms.

“Well, Daddy was born in 2004. What year is it now?” He asked. He caught Gen shooting him a warm smile, as he always did when he worked with the children on some kind of learning opportunity.

“2042.” She said with confidence. He nodded.

“So what is 42-4?” He asked next. She hummed, running the numbers in her head. Her little brother Tezuma opened his mouth to respond, but with a wink and a finger to his lips, he closed it.

“38! Wow Daddy, you’re almost 40.” She said in surprise.

“Yes, yes I am. Your old Dad is getting old, princess.” He said.

“If he’s old, I’d hate to see what that makes me.” Byakuya added with a laugh from the opposite couch.

“Rika, come and sit with the other children, please. It’s time to eat.” Gen called from where he was laying out plates of food. Rika jumped off of his lap, running over to her other parent.

“Did you have a nice day?” Tsukasa asked as they stood up to get food. Senku nodded, pressing a quick kiss to Gen’s smiling mouth when he handed him a plate next.

“Thanks. Yeah, actually. Come on, I’ll explain the major breakthrough I had.” He nodded towards the couch again. Chrome joined them, and they were all deep in a discussion about his latest project when Yuzuriha called them in for cake.

“What are you going to wish for, Daddy?” Tezuma asked as Gen picked him up so he could watch. Senku shook his head, holding a finger against his mouth.

  
“You can’t tell people that, bud. It won’t come true.” He said. Tezuma’s blue eyes widened in horror, and he turned to his other parent to confirm. Gen nodded, a grave look crossing his face.

“Daddy is right, sweetie. But it’s okay, now you know.” He soothed. Tezuma let out a relieved sigh.

“Thanks for telling me.” He said, pressing his forehead against Gen’s.

After the candles were blown out and cake had been distributed, Senku caught Gen’s hand.

“Senku-chan?” He asked as his husband pulled him in to his arms.

“Thank you for today.” He said. Gen smiled up at him, returning his embrace.

“Anything for my soulmate.” He promised, leaning up to kiss him.

“Seriously. This is one of the best birthdays I’ve ever had.” Senku added when they pulled apart.

“There will be more fun later.” Gen promised with a wink before turning away. Senku grinned, then turned around to take his place back on the couch.

Hours later and his house was blissfully silent. Senku stood in his kitchen, putting away the rest of the layovers when Gen’s arms wrapped around him.

“Kids in bed?” He asked, smiling as he leaned back against him. Gen nodded, snuggling closer.

“Yeah. And tomorrow is Sunday, so if you wanted to…” He leaned up, whispering in Senku’s ear his plans. Senku grinned, turning around to cup Gen’s face in his hands.

“Really? God I love you.” He said, pulling him in for an intense kiss. Gen laughed before moaning, stepping closer. They parted with matching grins before Gen took two steps back and turned to run towards they bedroom. Senku shook his head, and found himself chasing after him. As they landed on the bed, Gen’s tongue parting his lips, Senku mentally decided that this was definitely one of the best birthdays ever.

**Author's Note:**

> Thank you for your support this week, everyone!


End file.
